1. Field of the Invention
The present invention relates to a method for forming a fine pattern and a coating agent for pattern fining.
2. Related Art
Methods for forming fine patterns by using resist have been used in the manufacture of various products. Particularly, further fining of resist patterns is requested in semiconductor elements, along with an enhancement of semiconductor performance, and thus, investigations are being conducted in various aspects.
As a method for forming such a fine resist pattern, there has been proposed a new negative type developing process which uses a combination of a positive type chemically amplified resist composition, that is a chemically amplified resist composition which acquires increased solubility in alkali developer liquids when exposed, and a developer liquid containing an organic solvent (see, for example, Patent Document 1). A positive type chemically amplified resist composition acquires increased solubility in alkali developer liquids when exposed, but at this time, the solubility in organic solvents is relatively decreased. Therefore, in a negative type developing process, unexposed areas of a resist film are dissolved and removed by an organic developer liquid, and thus a resist pattern is formed. Thus, it is believed that negative type developing processes are advantageous in the formation of trench patterns or hole patterns as compared with conventional positive type developing processes.
For such reasons, there has been a demand for a method for forming a finer resist pattern while advantages of a negative type developing process are maintained.
Furthermore, as a method for further fining a resist pattern formed by using a resist composition, a method of fining a resist pattern including forming a coating film by coating a commercially available coating agent such as SAFIER (registered trade mark) (manufactured by TOKYO OHKA KOGYO Co., Ltd.) on a resist pattern formed by a positive type developing process using a positive type photoresist and heating the resist pattern with a coating film formed thereon to shrink the coating film is known.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2008-292975